According to this quote " a mistake will not affect assent unless it is a mistake of both parties and is as to the existence of some quality which makes the thing without the quality essentially different from the thing it is believed to be", by Lord Atkin in Bell v Lever Bros [1932] AC 161

Can and how can this statement regarding common mistakes as to the quality also apply to unilateral mistakes as to identity where one party is mistaken as to the other party's attributes?